Develop Reference

Unable to add Kotlin Android Extensions to my android studio

hen i try to add kotlin-android-extensions via:
apply plugin: 'kotlin-android-extensions'
to my project Android Studio tells me Plugin with 'kotlin-android-extensions not found??
What is going wrong? I am Running Android Studio

Kotlin Android Extensions has been deprecated for two years and should not be used in new products.
As of Kotlin 1.8, it is not available at all anymore.
I don't think they've officially turned it off yet, since Kotlin 1.8 hasn't officially been released, so there is probably some config issue in your project's Gradle files, but it doesn't matter, because you should not rely on a plugin that is going to stop working within 3 months.

It's deprecated Base on the google document
Kotlin Android Extensions is deprecated, which means that using Kotlin
synthetics for view binding is no longer supported.
for those who's wonder what the synthetic is. I should say a simple way to access to UI view id with kotlin which was possible by adding 'kotlin-android-extensions' in Gradle.
If your app uses Parcelable you can use 'kotlin-parcelize' instead of 'kotlin-android-extensions'.
If your app uses Kotlin synthetics for view binding, use this guide to migrate to Jetpack ViewBinding or Data Binding.
you can add any of it like the following
android {
...
buildFeatures {
dataBinding true
}
}

As "kotlin-android-extensions" is deprecated now, it's better to use view binding.
just head to the module-level build.gradle and add inside the android block:
buildFeatures {
viewBinding = true
}
then you will be able to use binding variables to reference views from your activities and fragments, all you need is here, but if you have any additonal questions to viewBinding just leave a comment

Why kotlin.collections is not implicitly imported after upgrading to jetpack compose 1.0.0-beta01?

After upgrading to jetpack compose 1.0.0-beta01, I tried to use arrayListOf, listOf from kotlin.collections but they seemed to not implicitly imported.

Your problem is probably related to what Kotlin version you are using.
I guess I went through a similar process as
you did when I was updating to the new version of Jetpack Compose library, where
as a "side effect" I was forced to update kotlin and kotlin-gradle-plugin version what then
indirectly caused your (and mine) problem. Following workaround should fix it.
Most likely you are using Kotlin 1.4.30 after updating Jetpack Compose to 1.0.0-beta01. Update Kotlin to fixed 1.4.31 version and your problem will be ALMOST "resolved".
I think the whole problem is somehow related to the following bug in 1.4.30 if
you are more interested https://youtrack.jetbrains.com/issue/KT-44845
Now after trying to build your project you will get a nice error saying This version (1.0.0-alpha13) of the Compose Compiler requires Kotlin version 1.4.30 but you appear to be using Kotlin version 1.4.31 which is not known to be compatible. Please fix your configuration (or `suppressKotlinVersionCompatibilityCheck` but don't say I didn't warn you!).
suppressKotlinVersionCompatibilityCheck is a compile argument which in my case I have set in module build.gradle file under android -> kotlinOptions this way:
kotlinOptions {
jvmTarget = JavaVersion.VERSION_1_8
useIR = true
//here -->
freeCompilerArgs += ["-P", "plugin:androidx.compose.compiler.plugins.kotlin:suppressKotlinVersionCompatibilityCheck=true"]
}
It also depends on the type of build.gradle files.
Read more about how to set those compile arguments at
Configure compiler arguments
where are described different ways for groovy and also for kotlin based gradle files.
Now you should be fine but bear in mind that you want to get rid of the suppressKotlinVersionCompatibilityCheck argument as soon as there is a new version of Jetpack Compose relying on a newer version of Kotlin.

Getting weird bugs when trying to update to Kotlin 1.4.0. How to make it work with Gradle and IntelliJ IDEA 2020.2.1?

Kotlin 1.4.0 is stable now. Therefor, I wanted to update my multi module Android project to use it. I set IDEA to use Kotlin plugin 1.4.0-release-IJ2020.2-1 and in my buildSrc build.gradle.kts using Kotlin DSL, I'm loading Kotlin for the jvm like this:
plugins {
kotlin("jvm") version "1.4.0"
}
My app level plugins block looks like this
plugins {
id("com.android.application")
id("com.google.gms.google-services")
kotlin("android")
kotlin("kapt")
id("kotlin-android-extensions")
id("androidx.navigation.safeargs.kotlin")
}
I have also added the Kotlin stdlib to my app level build.gradle.kts dependencies
implementation("org.jetbrains.kotlin:kotlin-stdlib:1.4.0")
When trying to build my project now, I get multiple Errors like the following:
'let((T) -> R): R' is only available since Kotlin 1.3.50 and cannot be used in Kotlin 1.3
I don't understand. How is gradle trying to use Kotlin 1.3 here? Any idea on how to fix this? Its working fine when using Kotlin v1.3.72 instead.
What I tried so far:
Clean Project
Invalidate caches and restart
Delete .gradle folder and restart
Fix broken classes paths
UPDATE
Forgot to mention that I'm also getting the following warning. How is it unsupported when it is stable?
> Configure project :buildSrc
WARNING: Unsupported Kotlin plugin version.
The `embedded-kotlin` and `kotlin-dsl` plugins rely on features of Kotlin `1.3.72` that might work differently than in the requested version `1.4.0`.

Maybe you should add the Kotlin standard lib to your dependencies explicitly?
dependencies {
implementation(kotlin("stdlib"))
}
With Kotlin 1.4 it is no longer required it add this dependency. The plugin applies the Stdlib by default to the projects it is applied to.
From the Kotlin 1.4 release notes:
You no longer need to declare a dependency on the stdlib library in any Kotlin Gradle project, including a multiplatform one. The dependency is added by default.
The automatically added standard library will be the same version of the Kotlin Gradle plugin, since they have the same versioning.

Jetpack Compose and Android Room compatibility

I am trying to set up Android Room in my Jetpack Compose project. However, when trying to add...
kapt "androidx.room:room-compiler:2.2.3"
... to the app build.gradle dependencies. My build fails with the error...
e: java.lang.NoSuchMethodError: org.jetbrains.kotlin.codegen.state.GenerationState$Builder.isIrBackend(Z)Lorg/jetbrains/kotlin/codegen/state/GenerationState$Builder;
Any insight as to why this is? Can we use Android Room with Jetpack Compose yet?

I'm pretty sure that we're still in a state where annotation processors (for Room, Retrofit, etc.) and the experimental Kotlin compiler are not getting along. The recommended approach at the moment is to isolate the Compose stuff in a module that is independent of modules that need annotation processors.

This is currently not supported as kapt does not play well with Jetpack Compose. This issue is being tracked here - https://issuetracker.google.com/issues/143232368

It's actually working, but not without some changes.
For a new project created with AndroidStudio 2020.3.1 Canary 2:
In build.gradle (Project):
Downgrade compose_version to 1.0.0-alpha07 and ext.kotlin_version to 1.4.10.
In build.gradle (Module):
Under composeOptions downgrade the composeCompilerVersion to 1.4.10.
Under dependencies change "androidx.compose.ui:ui-tooling:$compose_version" to "androidx.ui:ui-tooling:$compose_version".
In Main activity - change the import for the preview, as it depends on ui-tooling.
Add room dependencies.
Should work.
However, some newer Compose functionalities won't probably work, as they are explicitly stating, that one should use Kotlin version 1.4.20 and above.

How can I use newer release of android databinding library?

according to the bintray, newer version of the Android Databinding library has been released(1.0-rc5).
but if I'm correct, only compiler, compilerCommon and baseLibrary are updated, and dataBinder(which we actually include in build.gradle) is still 1.0-rc4.
Is there a way to use newer compiler, compilerCommon and baseLibrary while using dataBinder 1.0-rc4? Or is there already a 1.0-rc5 for dataBinder?

You can override the data-binding version in the build.gradle, like this:
dataBinding {
enabled true
version '1.1'
}

Never mind, in Android gradle plugin 1.5.0-beta1, dev team integrated data binding plugin into android plugin.
http://tools.android.com/tech-docs/new-build-system